In motor vehicles that include an internal combustion engine, there is usually at least one throttle valve which is used to control a fluid flow, in particular to control a flow of intake air which is supplied to the internal combustion engine. Throttle valves may be used to control the performance of the internal combustion engine.
A throttle shaft is pivotably supported in the throttle valve. A throttle is fastened to the throttle shaft. In the throttle valve shown in DE 42 20 022 A1, the throttle shaft includes a slot in which the throttle is fastened using screws. Measures are described in DE 42 20 022 A1 for reducing the leakage caused by the slot in the throttle shaft to the greatest extent possible.
With regard to throttle valves, it is important that the throttle be positioned very precisely inside the gas passage. Due to this problem, U.S. Pat. No. 4,682,758 shows an embodiment in which the throttle may be adjusted, using screws, in a direction transverse to the throttle shaft.
EP 0 879 136 B1 provides a throttle valve in which the throttle shaft includes projections which may be used to rivet the throttle to the throttle shaft.
DE 43 43 091 A1 shows a throttle valve in which a throttle is integrally extruded onto a throttle shaft which is pivotably supported in a throttle housing.
According to DE 197 03 296 A1, a thermosetting sealing means is applied in the liquid state using a cannula to a recess located between the throttle shaft and the throttle housing. Once hardened, the sealing means at the pivot bearing point creates a seal between the throttle shaft and the throttle housing.
According to DE 32 43 996 C1, a polymer coating is applied to the wall of the gas passage of the throttle valve. The polymer coating is used to reduce the leakage air when the throttle is in the closed position. The polymer coating on the wall of the gas passage creates unevenness, thereby causing an undesired turbulence in the fluid that is flowing through the gas passage.
DE 198 461 181 A1 shows a throttle valve in which the throttle housing includes transverse holes through which shaft stubs are shaped, from both sides, in the material of the throttle. The shaft stubs are preferably shaped in the material of the throttle via ultrasound. This method may only be used when the throttle is composed of a material that allows the shaft stubs to be shaped. Using the method shown in DE 198 41 181 A1, it is possible to position the throttle very precisely relative to the gas passage, but this method is rather elaborate.
U.S. Pat. No. 4,243,203 shows a throttle valve which includes a throttle shaft that is pivotably supported in a throttle housing, and which extends through a jacket that is integrally formed on the throttle. Screws are used to prevent the throttle from rotating.